Perception of Time (Score 1)

Humans are doomed to a sensation of accelerating time. For a 10 year old, a single year represents a full tenth of his life. For that same human 40 years later, a year represents a more slight 50th of his life. Perform this calculation with any unit of time and the trend would seem to be that time appears to accelerate with length of life, even if nothing else changes. It's just math.